- Patients with treated brain metastases (surgery, whole or stereotactic brain radiation) are allowed provided the lesions have been stable for at least 2 weeks and the patient is off steroids or is on a stable dose of steroids. Patients with brain metastases should not require use of enzyme-inducing antiepileptic drugs (e.g., carbamazepine, phenytoin, or phenobarbital) within 14 days before first dose and during study. Use of newer antiepileptics that do not produce enzyme induction drug-drug interactions (DDIs) is allowed.